I took an advantage of IFO thermalizing and did another OFI excitations. Since we didn't see any scatter shelves last time Jeff K suggested we try driving at OFI resonance frequency. I repeated the measurement following Varun's injection from last year and drove OFI at 0.65 Hz (not sure if this was the resonance frequency. I think Jeff said 5 Hz but I thought I should follow the old alog to start with). I could only get OFI L and T injections in before the IFO lost lock due to PI. While the shelve(s) at 10 Hz remain during OFI L excitations the shelves between 50-100 Hz seem to have disappeared. At 5 um pkpk OFI T excitation we didn't see anything in DARM compared to last year where you could see the shelves clearly.

OFI T injection at 5um didn't give us anything. I'll sneak in more T and Y injections next time when there're opportunities.